A computer system typically includes many different system components that communicate with each other via different types of interconnects such as shared links or direct or point-to-point links. Some systems have begun to incorporate so-called system-on-a-chip (SoC) devices in which multiple components are incorporated on a single semiconductor die. Furthermore, some SoCs can be incorporated as an embedded device into various other systems that are not personal computer (PC)-based.
Regardless of the type of system, as the number of components seeking to communicate increases, the likelihood of contention for resources such as interconnect bandwidth, destination components and so forth increases also. To prevent deadlocks and stalls in a system, an arbiter may be present to receive requests from multiple agents and arbitrate the requests to provide access grants to resources of the system. In some systems, arbitration is performed according to a priority privilege in which a certain number of grants are allowed to each requester to avoid a higher priority requester from starving lower priority requesters. Such priority schemes may provide for a static, dynamic or increment-based priority. Grant operation typically starts from the highest priority requester and proceeds to the lowest priority requester. In some systems, the lower priority requester can only receive a grant when higher priority requesters have no active requests or have exhausted their grant count.
Current arbitration schemes typically lack control over allocation of bandwidth and can lead to starvation of low priority requesters, particularly under heavy/bursty traffic and when wider data transfer length is supported and more and more peripherals are present in a system.